1. Field of the Invention
The present invention relates to a selection apparatus which is to be used when an operator selects a desired function from a plurality of functions of a multi-function apparatus using, in particular, the operator's line of sight.
2. Description of the Related Art
A "function operation," which requires an operator of an apparatus to visually observe changes in circumstances during operation so as to operate the apparatus in accordance with the circumstances thus observed, is very common in apparatuses produced as consumer goods as well as in apparatuses for use in special fields. Typical examples of such apparatuses produced as consumer goods include automobiles and cameras. Typical examples of the apparatuses for use in special fields include machining apparatuses equipped with a microscope and remote control apparatuses using a video camera.
In particular, in a functional apparatus, such as a camera or a microscope, in which the operator applies his or her eye to the eyepiece section when operating the apparatus, it is necessary that the switches and other operating members should be situated in such a way that the operator can be sure of their positions without a visual check. It would be inconvenient for the operator if he had to separate the eye from the eyepiece section upon each operation to be sure of the position of the relevant switch or operating member. Moreover, the need to visually check the position of the switch, etc. would make it impossible for the operator to visually observe changes in the circumstances, with the result that there is a fear that the apparatus will be prevented from being properly operated.
In view of this, various ideas have been proposed regarding the arrangement of switches, operating members, etc. of such apparatuses.
In the field of cameras, for example, an arrangement is generally adopted in which the release button is situated where the forefinger naturally comes to rest when the user holds the camera in his hands. Similarly, in a video camera, the recording start switch is generally situated where the thumb rests, and the scaling switches are arranged where the index and middle fingers are to be placed. Further, the plurality of function switches with which the camera is equipped are made in different sizes or provided with rough surfaces having different peculiar feels to the touch so that the switches may be easily identified, whereby it is possible for a multi-function apparatus to be correctly operated.
In functional apparatuses produced as consumer goods, a rapid reduction in size and weight is in progress with the increase in the number of functions. The reduction in size and weight has led to a substantial reduction in the surface area of the apparatus, resulting in a problem that all the switches cannot be arranged on the apparatus or, if they can, no space is available for imparting distinctive sizes and shapes to them. Further, as a result of the increase in the number of functions, there has emerged a problem that there is a limit to the variety of rough surfaces, i.e., the different peculiar feels to the touch, to be imparted to the plurality of switches.
FIG. 1 shows an example of the layout of basic function selecting switches in a conventional video camera. In the drawing, numeral 1 indicates a video camera having a body 2, on a side surface of which there are arranged: a switch 3 for effecting superimposition of a character title on an image, a switch 4 for effecting fade-in and out, a switch 5 for imparting dates to pictures, a switch 6 for switching between auto and manual focusing, etc. Further, scaling switches 7 and 8 for scaling in the tele-end and wide-angle-end directions are arranged in that section of the body 2 where the index and middle fingers of the photographer lie. When the photographer 9 photographs a subject 11 while observing it through a finder 10 in the body 2, he manipulates the above switches 3 through 8 as needed.
Thus, in the conventional video camera 1, it is necessary to manipulate a number of switches, 3 through 8, during photographing, which is not only inconvenient but may also lead to an uncertain manipulation of the switches, resulting in an erroneous operation.
In an actual multi-function video camera, more switches are provided in addition to the switches 3 through 8 shown in FIG. 1. Thus, it is practically impossible to correctly manipulate such a large number of switches without visually checking their positions.
To overcome this problem, the present inventor proposed in Japanese Patent Applications No. 3-257795 and 4-202 a system (which will be referred to as the "prior invention") according to which camera function menus are displayed in the finder through which the photographer looks when photographing and, from the line of sight of the photographer, which is observed by a line-of-sight detector arranged in the eyepiece section, it is determined at which of the function menus displayed in the finder he is gazing. Then, the function corresponding to the function menu the photographer is gazing at is caused to be carried out, thus enabling the photographer to properly select a desired function without separating his eye from the finder.
In the above-described system of the previous invention, selection of a menu from the selectable function menus displayed in the finder is executed far less often as compared with the operation of the entire apparatus (i.e., photographing). Therefore, there is no need to constantly display the function menus in the finder. If constantly displayed in the finder, the menus would become a nuisance to the user, who keeps looking through the finder throughout the operation. Further, for the function menus to be displayed in the finder in such a way as not to be an obstacle to the operation the user performs while looking through the finder, the number of function menus must be limited.
In addition, the above system, in which the line of sight of the operator is constantly observed so as to make the apparatus always ready for any of the functions looked at by the operator, has a problem in that the operator may look at the wrong menu, resulting in malfunction of the camera.